SMART syndrome: Classic transient symptoms leading to an unusual unfavorable outcome

Stroke-Like Migraine Attacks After Radiation Therapy (SMART) Syndrome: A Comprehensive Review

PURPOSE OF REVIEW

SMART syndrome is a delayed complication of cranial irradiation that can be misconstrued as tumor recurrence or some other intracranial neurological disease. Recognition of this clinical syndrome is imperative as it can obviate the need for invasive diagnostic testing and can provide reassurance to both the patient and their loved ones.

RECENT FINDINGS

SMART syndrome is generally considered a reversible clinical syndrome; however, neurological deficits may become permanent. Pathophysiology of SMART syndrome may involve cerebrovascular autoregulation impairment, neuronal dysfunction leading to trigeminovascular system impairment and/or cortical spreading depression, and seizures. In addition to MRI brain with gadolinium, other imaging modalities, such as CT perfusion, MR perfusion, MR spectroscopy, and FDG PET/CT, aid in arriving to the diagnosis sooner. Patients should also undergo electroencephalogram in order to promptly identify and treat seizures. There are currently no clear guidelines on how to effectively treat SMART syndrome, but treatment may involve anti-seizure medication, anti-hypertensives, anti-platelet, and steroid therapy. This review provides a comprehensive understanding of the clinical characteristics of SMART syndrome from presentation to diagnostic evaluation. We also discuss radiographic features and treatment strategies for this rare disease. With increased radiotherapy utilization, prompt clinical recognition of SMART syndrome and further development of a comprehensive diagnostic approach to SMART syndrome utilizing newer radiographic modalities as well as treatment algorithms to effectively treat this clinical condition will be imperative.

A 15-Year-Old Girl With Sudden Onsent Reversible Neurologic Symptoms After Cranial Irradiation for Medulloblastoma

A 15-year-old girl with history of medulloblastoma was evaluated for headache and neurologic deficits 5 years after completion of initial radiation therapy and 3 years following completion of reirradiation. Neurologic examination was notable for new-onset left hemianopia, hemiparesis, and neglect. Magnetic resonance imaging showed extensive areas of cortical T2 prolongation and thickening involving the right parietal, occipital, and temporal lobes with associated extensive gyral enhancement. Upon spontaneous resolution of her weakness after 4 days, repeat magnetic resonance imaging showed resolution of the edema and gyral enhancement, suggestive of the diagnosis of stroke-like migraine attacks after radiation therapy (SMART syndrome). A review of SMART is provided in this case report.

Stroke-like Migraine Attacks after Radiation Therapy (SMART) Syndrome Followed by Cerebral Infarction

A 36-year-old man with a history of irradiation for acute lymphoblastic leukemia developed headache with cortical dysfunction lasting for 4 weeks. The clinical features were consistent with stroke-like migraine attacks after radiation therapy (SMART) syndrome. Six months later, he developed cerebral infarction due to occlusions of the left anterior and middle cerebral arteries. This is the first case report describing SMART syndrome followed by severe cerebral infarction. Although an association between the two episodes was not assumed, this case indicates that protective therapies against infarction might need to be considered for patients with SMART syndrome.